公開課鏈接渡一教育貪喫蛇連接
<body>
<div class="content">
<div class="btn startBtn"><button></button></div>
<div class="btn pauseBtn"><button></button></div>
<div id="snakeWrap">
</div>
</div>
.content{
width: 640px;
height: 640px;
margin: 50px auto;
position: relative;
}
.btn{
width: 100%;
height: 100%;
position: absolute;
left: 0;
top: 0;
background-color: rgba(0,0,0,0);
z-index: 1;
}
.btn button{
background: none;
border:none;
background-size: 100% 100%;
cursor: pointer;
outline: none;
position: absolute;
left: 50%;
top: 50%;
}
.startBtn button{
width: 200px;
height: 100px;
background-image: url("../開始遊戲.png");
margin-left: -100px;
margin-top: -50px;
}
.pauseBtn{
display: none;
}
.pauseBtn button{
width: 70px;
height: 70px;
background-image: url("../遊戲暫停.png");
margin-left: -35px;
margin-top: -35px;
}
#snakeWrap{
position: relative;
width: 600px;
height: 600px;
background: #225675;
border:20px solid #7dd9ff;
}
.snakeHead{
background-image: url("../蛇頭.png");
background-size: cover;
}
.snakeBody{
background-color: #9ddbb1;
border-radius: 50%;
}
.food{
background: url("../食物.png") no-repeat;
background-size: 100% 100%;
}
var sw = 20, // 一個方塊的寬度
sh = 20, // 高度
tr = 30, // 行數
td = 30; // 列數
var snake = null, // 蛇的實例
food = null, // 食物的實例
game = null; // 遊戲實例
// 方塊構造函數
function Square(x,y,classname) {
this.x = x*sw;
this.y = y*sh;
this.class = classname;
this.viewContent = document.createElement('div');
this.viewContent.className = this.class;
this.parent = document.getElementById('snakeWrap');
}
Square.prototype.create = function(){ // 創建方塊dom
this.viewContent.style.position='absolute';
this.viewContent.style.width = sw+'px';
this.viewContent.style.height = sh + 'px';
this.viewContent.style.left = this.x +'px';
this.viewContent.style.top = this.y + 'px';
this.parent.appendChild(this.viewContent)
}
Square.prototype.remove = function() {
this.parent.removeChild(this.viewContent);
}
// 蛇
function Snake () {
this.head = null; //蛇頭
this.tail = null; // 蛇尾
this.pos = []; // 存儲蛇身上的每一個方塊的位置
this.directionNum = { // 存儲蛇走的方向,用一個對象來表示
left:{
x:-1,
y:0,
rotate:180 // 蛇頭旋轉角度
},
right:{
x:1,
y:0,
rotate:0
},
up:{
x:0,
y:-1,
rotate:-90
},
down:{
x:0,
y:1,
rotate:90
}
}
}
Snake.prototype.init = function() {
// 創建蛇頭
var snakeHead = new Square(2,0,'snakeHead');
snakeHead.create();
this.head = snakeHead; // 存儲蛇頭信息
this.pos.push([2,0]) // 存儲蛇頭位置
// 創建蛇身體
var snakeBody1 = new Square(1,0,'snakeBody');
snakeBody1.create();
this.pos.push([1,0]) // 存儲蛇身1位置
var snakeBody2 = new Square(0,0,'snakeBody');
snakeBody2.create();
this.tail = snakeBody2; // 存儲蛇尾信息
this.pos.push([0,0]) // 存儲蛇身1位置
// 形成鏈表關係
snakeHead.last = null;
snakeHead.next = snakeBody1;
snakeBody1.last = snakeHead;
snakeBody1.next = snakeBody2;
snakeBody2.last = snakeBody1;
snakeBody2.next = null;
// 給蛇添加一個屬性,用來表示蛇走的方向
this.direction = this.directionNum.right; // 默認往右走
}
// 獲取蛇頭的下一個位置對應的元素,要根據元素做不同的事情
Snake.prototype.getNextPos = function() {
var nextPos = [
this.head.x/sw+this.direction.x,
this.head.y/sh+this.direction.y
]
// 下個點是自己,遊戲結束
var selfCollied = false; //是否撞到了自己
this.pos.forEach(function(value) {
if(value[0]==nextPos[0] && value[1]==nextPos[1]){
selfCollied = true;
}
});
if(selfCollied){
console.log('撞到了自己');
this.strategies.die.call(this);
return;
}
// 下個點是圍牆,遊戲結束
if(nextPos[0]<0 || nextPos[1]<0 || nextPos[0]>td-1 || nextPos[1]>tr-1){
console.log('撞到了牆');
this.strategies.die.call(this);
return;
}
// 下個點是食物,喫
if(food && food.pos[0]==nextPos[0] && food.pos[1]==nextPos[1]){
// 如果這個條件成立說明現在蛇頭要走的下一個點是食物的那個點;
console.log('喫到食物了');
this.strategies.eat.call(this);
return;
}
// 下個點什麼都不是,走
this.strategies.move.call(this);
};
// 處理碰撞後要做的事
Snake.prototype.strategies = {
move:function(format) { // 該參數用於決定是否刪除蛇尾
// 創建新身體,在舊蛇頭的位置
var newBody = new Square(this.head.x/sw,this.head.y/sh,'snakeBody');
// 更新鏈表的關係
newBody.next = this.head.next;
newBody.next.last = newBody;
newBody.last = null;
this.head.remove(); // 把舊蛇頭從原來的位置刪除
newBody.create();
// 創建蛇頭:蛇頭下一個點
var newHead = new Square(this.head.x/sw+this.direction.x,this.head.y/sh+this.direction.y,'snakeHead');
// 更新鏈表的關係
newHead.next = newBody;
newHead.last = null;
newBody.last = newHead;
newHead.viewContent.style.transform = 'rotate('+this.direction.rotate+'deg)';
newHead.create();
// 更新蛇身上每一個方塊的座標
this.pos.splice(0,0,[this.head.x/sw+this.direction.x,this.head.y/sh+this.direction.y]);
this.head = newHead; //更新this.head
if(!format){ // false: 需要刪除(處理喫之外的操作)
this.tail.remove();
this.tail = this.tail.last;
this.pos.pop();
}
},
eat:function(){
this.strategies.move.call(this,true);
createFood();
game.score++;
},
die:function(){
game.over();
}
}
snake = new Snake();
// snake.init();
// 創建食物
function createFood(){
// 食物的隨機座標
var x = null;
var y = null;
var include = true; // 循環跳出的條件,true表示食物座標在蛇身上,false:表示不在
while(include){
x = Math.round(Math.random()*(td-1));
y = Math.round(Math.random()*(tr-1));
snake.pos.forEach(function(value){
if(x!=value[0] && y!=value[1]){
// 座標不在蛇身上
include = false;
}
})
}
// 生成食物
food = new Square(x,y,'food');
food.pos = [x,y]; // 存儲食物的座標,用於跟蛇頭下一個走的點作對比
var foodDom = document.querySelector('.food');
if(foodDom){
foodDom.style.left = x*sw +'px';
foodDom.style.top = y*sh +'px';
}else{
food.create();
}
}
// 創建遊戲邏輯
function Game(){
this.timer = null;
this.score = 0;
}
Game.prototype.init = function(){
snake.init();
createFood();
document.onkeydown = function(ev) {
// 用戶按下左鍵, 蛇不能是正在往右走的
if(ev.which == 37 && snake.direction != snake.directionNum.right){
snake.direction = snake.directionNum.left;
}else if(ev.which == 38 && snake.direction != snake.directionNum.down){
snake.direction = snake.directionNum.up;
}else if(ev.which == 39 && snake.direction != snake.directionNum.left){
snake.direction = snake.directionNum.right;
}else if(ev.which == 40 && snake.direction != snake.directionNum.up){
snake.direction = snake.directionNum.down;
}
}
this.start();
}
Game.prototype.start = function(){
// 開始遊戲
this.timer = setInterval(function(){
snake.getNextPos();
},200);
}
Game.prototype.pause = function() {
clearInterval(this.timer);
}
Game.prototype.over = function() {
clearInterval(this.timer);
alert('你的得分爲:'+ this.score);
// 遊戲回到最初始的狀態
var snakeWrap = document.getElementById('snakeWrap');
snakeWrap.innerHTML = '';
snake = new Snake();
game = new Game();
var startBtnWrap = document.querySelector('.startBtn');
startBtnWrap.style.display = 'block';
}
// 開啓遊戲
game = new Game();
var startBtn = document.querySelector('.startBtn button');
startBtn.onclick = function(){
startBtn.parentNode.style.display = 'none';
game.init();
}
// 暫停遊戲
var snakeWrap = document.getElementById('snakeWrap');
var pauseBtn = document.querySelector('.pauseBtn button');
snakeWrap.onclick = function() {
game.pause();
pauseBtn.parentNode.style.display='block';
}
pauseBtn.onclick = function() {
game.start();
pauseBtn.parentNode.style.display='none';
}